My pin: Find a large, clear plastic bin to fill half way with water. Place the sink or float sign on the front. Have students bring reasonable items from home to see if it will sink or float! As the teacher, also provide objects to test out. This is a fun, hands on activity to teach kids about weight and whether objects will float or sink! Following the experiment, it is good to make a chart of the things that sank and float! Totally recommend for a large/whole group and K-2nd grade!